This invention relates in general to communication methods, systems, and apparatuses, and in particular to ultra-wide band based wireless communication methods, systems, and apparatuses.
The demand for short to medium range, high speed connectivity for multiple digital devices in a local environment continues to rise sharply. For example, many workplaces and households today have many digital computing or entertainment devices such as desktop and laptop computers, television sets and other audio and video devices, DVD players, cameras, camcorders, projectors, handhelds, and others. Multiple computers and television sets, for instance, have become common in American households. In addition, the need for high speed connectivity with respect to such devices is becoming more and more important. These trends will inevitably increase even in the near future.
As the demand for high speed connectivity increases along with the number of digital devices in typical households and workplaces, the demand for wireless connectivity naturally grows commensurately. High-speed wiring running to many devices can be expensive, awkward, impractical and inconvenient. High speed wireless connectivity, on the other hand, offers many practical and aesthetic advantages, which accounts the great and increasing demand for it. Ideally, wireless connectivity in a local environment should provide high reliability, low cost, low interference caused by physical barriers such as walls or by co-existing wireless signals, security, and high speed data transfer for multiple digital devices. Existing narrowband wireless connectivity techniques do not provide such a solution, having problems such as high cost, unsatisfactory data transfer rates, unsatisfactory freedom from signal and obstacle related interference, unsatisfactory security, and other shortcomings. In fact, the state of the art does not provide a sufficiently satisfactory solution for providing high speed wireless connectivity for multiple digital devices in a local environment.
The state of the art in wireless connectivity generally includes utilization of spread spectrum systems for various applications. Spread spectrum techniques, which spread a signal over a broad range of frequencies, are known to provide high resistance against signal blocking, or “jamming,” high security or resistance against “eavesdropping,” and high interference resistance. Spread Spectrum techniques have been used in systems in which high security and freedom from tampering is required. Additionally, Code Division Multiple Access (CDMA), a spread spectrum, packet-based technique, is used in some cellular phone systems, providing increased capacity in part by allowing multiple simultaneous conversation signals to share the same frequencies at the same time.
Known spread spectrum and modulation techniques, including CDMA techniques, direct sequence spread spectrum (DSSS) techniques, time hopping spread spectrum (THSS) techniques, and pulse position modulation (PPM) techniques, do not satisfactorily provide wireless connectivity in a local environment, including high reliability, low cost, low interference, security, and high speed data transfer for multiple digital devices. In addition, known UWB transmission and communication methods and systems lack satisfactory quality in areas that can include flexibility, adaptivity and adaptive trade-off capabilities in areas such as power usage, range, and transfer rates, and low cost implementation.
A number of U.S. and non-U.S. patents and patent applications discuss spread spectrum or UWB related systems for various uses, but are nonetheless in accordance with the above described state of the art. The U.S. and non-U.S. patents and patent applications discussed below are hereby incorporated herein by reference in their entirety.
There are several Japanese patents and applications in some of these areas. Japanese patent application JP 11284599, filed on Mar. 31, 1998 and published on Oct. 15, 1999, discusses spread spectrum CDMA mobile communications. Japanese patent application JP 11313005, filed on Apr. 27, 1998 and published on Nov. 9, 1999, discusses a system for rapid carrier synchronization in spread spectrum communication using an intermittently operative signal demodulation circuit. Japanese patent application JP 11027180, filed on Jul. 2, 1997 and published on Jan. 29, 1999, and counterpart European application EP 0889600 discuss a receiving apparatus for use in a mobile communications system, and particularly for use in spread spectrum Code Division Multiple Access communications between a base station and a mobile station. Japanese patent application JP 21378533, filed on Nov. 18, 1988 and published on May 25, 1990, discusses a transmitter for spread spectrum communication.
A number of U.S. patents and published applications discuss spread spectrum or UWB in various contexts. U.S. Pat. No. 6,026,125, issued Feb. 15, 2000 to Larrick, Jr. et al., relates to utilization of a carrier-controlled pulsed UWB signal having a controlled center frequency and an adjustable bandwidth. U.S. Pat. No. 6,351,652, issued Feb. 6, 2002 to Finn et al., discusses impulse UWB communication. U.S. Pat. No. 6,031,862, issued Feb. 29, 2000 to Fullerton et al., and related patents including U.S. Pat. Nos. 5,677,927, 5,960,031, 5,963,581, and 5,995,534, discuss a UWB communications system in which impulse derived signals are multiplied by a template signal, integrated, and then demodulated, to increase the usability if signals which would otherwise be obscured by noise. U.S. Pat. No. 6,075,807, issued Jun. 13, 2000 to Warren et al., relates to a spread spectrum digital matched filter. U.S. Pat. No. 5,177,767, issued Jan. 5, 1993 to Kato, discusses a “structurally simple” wireless spread spectrum transmitting or receiving apparatus which is described as eliminating the need for code synchronization. U.S. Pat. No. 6,002,707, issued Dec. 14, 1999 to Thue, relates to radar system using a wide frequency spectrum signal for radar transmission to eliminate the need for very high energy narrow pulse transmitter and receiver systems. U.S. Pat. No. 5,347,537, issued Jun. 21, 1994 to Mori, et al., and related patents including U.S. Pat. Nos. 5,323,419 and 5,218,620, discuss a direct sequence spread spectrum transmitter and receiver system. U.S. Pat. No. 5,206,881, issued Apr. 27, 1993, discusses a spread spectrum communication system attempting to use rapid synchronization of pseudonoise code signals with data packet signals.
A number of published PCT international applications also discuss spread spectrum or UWB in various contexts. PCT international application, publication number WO 01/39451 published on May 31, 2001, discusses a waveform adaptive transmitter for use in radar or communications applications. PCT international application, publication number WO 01/93441, published on Dec. 6, 2001, discusses a UWB high-speed digital communication system using wavelets or impulses. PCT international application, publication number WO 01/99300, published on Dec. 27, 2001, discusses wireless communications using UWB signaling. PCT international application, publication number WO 01/11814, published on Feb. 15, 2001, discusses a transmission method for broadband wired or wireless transmission of information using spread spectrum technology.
In accordance with all of the above, there is a need in the art for an improved communication methods and systems. Additionally, there is a need in the art for methods and systems to provide wireless connectivity between multiple digital devices in a local environment.